The present invention relates to a seat belt connecting device which is used for connecting an outer belt composed of a lap belt portion and a shoulder belt portion to an inner belt, especially to a seat belt connecting device provided with a mechanism by which the outer belt is substantially prevented from being shifted at an emergency time such as upon an impact of a vehicle.
In the seat belt system for a vehicle of such a type that the lap belt portion which protects the lap of an occupant and the shoulder belt portion which protects the upper half of the occupant's body from his shoulder to his chest are formed by one outer belt, the outer belt is connected to the inner belt at a position between the lap belt portion and the shoulder belt portion.
One end of the inner belt is connected to the connecting device and the outer belt is shiftably supported thereby.
The occupant can freely move on his seat since the outer belt is shiftably supported by the seat belt connecting device.
Conventionally, as the seat belt connecting device of this type, a rectangular ring-shaped connector which connects the outer belt to the inner belt while shiftably supporting the outer belt has been used.
The seat belt system using the above described conventional seat belt connecting device has a defect that the outer belt relatively shifts with respect to the seat belt connecting device at an emergency time such as upon an impact of the vehicle, namely, that the lap belt portion shifts to the side of the shoulder of the occupant or the shoulder belt portion shifts to the side of the lap of the occupant.
When the lap belt portion shifts to the side of the shoulder of the occupant, the amount of the movement of the upper half of the occupant is increased and when the shoulder belt portions shifts to the side of the lap of the occupant, so-called submarine phenomenon occurs. In both cases, the occupant is not surely protected by the seat belt.
In particular, in the automatic type seat belt system wherein the inner belt is withdrawn from a retractor, the relative shift of the outer belt with respect to the seat belt connecting device is apt to occur at an emergency time.
Accordingly, one object of the present invention is to provide an improved seat belt connecting device for connecting an outer belt to an inner belt, by which the safety of an occupant is more improved at an emergency time such as upon an impact of a vehicle.
Another object of the present invention is to provide a seat belt connecting device for connecting an outer belt to an inner belt provided with an outer belt supporting member which shiftably supports the outer belt at usual times and stops the outer belt from being shifted at an emergency time.